Exercise device



FIG. 1 is an isometric view of an exercise device showing my new design:

FIG. 2 is a front elevational view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a bottom view thereof;

FIG. 5 is a side elevational view thereof; the opposite side being a mirror image thereof; and,

FIG. 6 is a rear elevational view thereof.

The broken lines illustrate portions of the exercise device which form no part of the claimed design. 

The ornamental design for an exercise device, as shown and described. 